On Friday, September 4, 2020 8:28:02 PM CEST Linus Lüssing wrote: > For DHCPv6: This is even trickier... DHCPv6 potentially uses > non-broadcast multicast addresses. However according to RFC8415, section > 7.1 it seems that currently multicast is only used from a DHCPv6 client > to a DHCPv6 server, but not the other way round. > > Working through the gateway feature part in batadv_interface_tx() it can > be inferred that a DHCPv6 packet to a DHCP client would have been the only > option for a DHCPv6 multicast packet to be sent via unicast through the > gateway feature. Ergo, the newly introduced claim check won't wrongly > drop a DHCPv6 packet received via the gateway feature either.
I also don't get this part. Maybe it helps if you can explain the two directions (client -> server, server -> client), and in which cases there can be multicast, and then describe why your check is sufficient? > > Fixes: e32470167379 ("batman-adv: check incoming packet type for bla") > Signed-off-by: Linus Lüssing <linus.luess...@c0d3.blue> > --- > net/batman-adv/bridge_loop_avoidance.c | 6 ++++-- > 1 file changed, 4 insertions(+), 2 deletions(-) > > diff --git a/net/batman-adv/bridge_loop_avoidance.c > b/net/batman-adv/bridge_loop_avoidance.c index d8c5d317..9603a6d0 100644 > --- a/net/batman-adv/bridge_loop_avoidance.c > +++ b/net/batman-adv/bridge_loop_avoidance.c > @@ -1848,7 +1848,8 @@ bool batadv_bla_rx(struct batadv_priv *bat_priv, > struct sk_buff *skb, > > if (unlikely(atomic_read(&bat_priv->bla.num_requests))) > /* don't allow broadcasts while requests are in flight */ > - if (is_multicast_ether_addr(ethhdr->h_dest) && is_bcast) > + if (is_multicast_ether_addr(ethhdr->h_dest) && > + (!is_broadcast_ether_addr(ethhdr->h_dest) || is_bcast)) > goto handled; Isn't this exactly the same logic as it was before? is_multicast == 0, is_bcast = 0 => 0 is_multicast == 0, is_bcast = 1 => 0 is_multicast == 1, is_bcast = 0 => 0 is_multicast == 1, is_bcast = 1 => 1 > > ether_addr_copy(search_claim.addr, ethhdr->h_source); > @@ -1885,7 +1886,8 @@ bool batadv_bla_rx(struct batadv_priv *bat_priv, > struct sk_buff *skb, } > > /* if it is a broadcast ... */ > - if (is_multicast_ether_addr(ethhdr->h_dest) && is_bcast) { > + if (is_multicast_ether_addr(ethhdr->h_dest) && > + (!is_broadcast_ether_addr(ethhdr->h_dest) || is_bcast)) { > /* ... drop it. the responsible gateway is in charge. > * > * We need to check is_bcast because with the gateway Same here.
signature.asc
Description: This is a digitally signed message part.